Antigua
A small colonial city and UNESCO heritage site an hour west of Guatemala City, surrounded by three volcanoes: Agua, Acatenango and Fuego. It sits at 1,530 m. Cobblestone streets, low pastel houses and ruined churches. Compact enough to cross on foot in twenty minutes, and the base most travellers use for the volcano hikes.
Volcán Acatenango and Fuego
Two days, 3,976 m, camp facing Fuego erupting all night. The hardest and best thing on this list. Slot it in after Antigua if your legs and lungs are up for it. Talk to your doctor about altitude medication before you book.